


Darker than that

by thistels



Category: Supernatural
Genre: Alternate Universe - Canon Divergence, Alternate Universe - Dark, Blood Drinking, Bloodplay, Dark Dean Winchester, Dark Sam Winchester, Demon Dean, Dirty Talk, Episode Related, Episode: s10e03 Soul Survivor, First Time, M/M, Mentions of past Jessica Moore/Sam Winchester, Oral Sex, Rough Oral Sex, Sam Winchester Loves Dean Winchester, Sam is back on demonblood, Tiny mention of Sam wanting to kill himself if Dean dies
Language: English
Status: In-Progress
Published: 2016-07-28
Updated: 2016-07-28
Packaged: 2018-07-27 09:42:38
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 5,067
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7613179
Author URL: https://archiveofourown.org/users/thistels/pseuds/thistels
Summary: <blockquote class="userstuff">
              <p>This is was basically my headcanon for S10E03 ever since the promo-trailer came out. Only, in the series Cas shows up and crashes the party before the boys can get to where they would obviously have gone. This is a correction of that episode, and goes AU after the epic scene with Demonic Dean, the demon-knife and Sam. </p><p>It's basically Sam taking up drinking demon-blood again and the boys going dark-side together. </p><p>Might not be a fic for people who can't stand Castiel getting his feathers ruffled a bit. Or a lot. Like, a lot a lot. The boys aren't very nice to their angel once they go off the deep end.</p>
            </blockquote>





	Darker than that

Objectively Sam knows that he should have pressed the demon-killing knife harder into the soft flesh of Dean’s throat. Hell, Dean had even asked for it. Daring Sam to do it, because he knew just as well as Sam did that there was no way the younger brother would be able to kill Dean. His brother, his hero, his best friend, his _soulmate_ , however ridiculous that description sounded describing two grown men with military-boots, scars and leatherjackets. But he should have, none the less. He knows it, he feels it in his entire body as Dean takes a daring step toward him, not caring that the edge of the deadly knife digs deeper into his skin, threatening to break it unless Sam backs down. He should have pressed on. He should have taken a step forward, made a quick slashing movement and it would all have been over in a second. He should have done it. He could have slashed his own wrists with the very same knife after that, if the thought of living without his brother had been too much. Their bodies would rot together in the bunker for as long as time would go on. The world would forget the Winchester-name and it would probably be better off without their good intentions unleashing one monster capable of ruining the world after the other, each worse than the previous. 

He really should have done it. For all the things he’d told Dean after his brother came back from purgatory, after he had stopped the trials to Sam’s life and after the whole mess with Gadreel, Sam was a hypocrite of epic proportions. One simple movement of his wrist and the entire thing would have been done. The world would have been a better place. It wasn’t even really _Dean_ behind those black eyes, it was something else, something dark and twisted just wearing his face. Dean, the real Dean, would have wanted Sam to end him, he wouldn’t have wanted some demonic shell of himself wreaking havoc on the world. That was what Sam had tried to tell himself as he braced the knife between his and the demon’s body, trying to fool himself into actually believing that he could do it, just because he knew that he should. 

But it _was_ Dean. It really was. It wasn’t just because the demon kept saying it was his brother, it was the way it looked at him. The way his words were Dean’s, the way Dean would have been if he wasn’t burdened by the shit that had been thrust upon him since he was four years old. It was how he had been, deep down, ever since he came back from hell, only now he didn’t feel morally compelled to shove all of that down and hide it away from the rest of the world.

Sam had loved his brother since the day he came back from Hell, but he’d been terrified when Dean had told him what he’d done in the pit. He hadn’t been able to relate to the darkness within his brother though, not until he’d been in Hell himself. Only then he could understand how Dean had been affected, how his brother had fundamentally changed, how his soul had gotten corrupted beyond return. For a long time after that he’d had a hard time accepting that. Accepting that Dean wasn’t the kid he’d grown up with anymore, that his priorities had shifted and that the righteous man had died in hell once he’d accepted Alastair’s offer. But he figured that Hell had changed him as well. Because he wasn’t scared of that side of Dean anymore. He still loved his brother, for what he was now, not for the memory of what he had been. 

He loved him not despite his dark side but because of his dark side, because of the way Dean’s eyes light up when he held a knife is his hands or got them stained with blood. This Dean was just as beautiful as all earlier versions of his brother had been, and in the instances where he lost himself to the dark pull of the mark he was finally unconcerned with the rest of the world. All the things that usually made his shoulders sag like the weight of the world was on him disappeared. The need to please a father who had been dead for years and indifferent enough to have been dead several years before that didn’t suffocate him. The guilt didn’t burn him from the inside out until he forgot why he even kept going. In those instances he was just Dean, Sam’s brother, content. Taking things for himself, doing what he wanted, because he wanted it. He didn’t deny himself anything, the way he’d done his entire life. He could look Sam in the eye without self-loathing bleeding through and he recognized that his own life mattered, that he deserved to live and to have good things. It was a beautiful thing to watch, to be close to, however fucked up the things his brother wanted for himself might be.

So Sam couldn’t bring himself to kill his brother, despite the warning in his eyes that said that if Sam didn’t _do it_ (he felt a shiver go through his entire body at the way Dean had said those words with the sharp blade digging into his throat) he’d regret it. But there was no way that he could kill his brother, not the teenager, not the young man who’d come to get him from Stanford, not the man burdened by centuries in hell and not this version with eyes swallowed up by black smoke. He loved his brother more than everything else, he always had and he always would, not matter how deep he tried to bury it or how tough he talked. He’d tried replacing his brother with Jessica, had found Dean’s exact opposite in her, taken her to bed and immersed himself in the things she gave him that he could never have from Dean. He’d tried with Amelia, but that had been such a pale comparison that he didn’t even remember how her touch felt, it had washed away as soon as he had hugged Dean hours out of purgatory. Even when he was soulless his live had revolved around Dean, he’d trusted Dean to know what was best when he knew that something was wrong even though his instincts screamed to do the opposite of what his brother said.

All of those things didn’t matter though. That was just between Dean and himself, their stupid codependence threatening to bring the end of the world once again. He _should_ have killed the demon when he’d had the chance. He shouldn’t have put the lives of millions of people in danger just because he couldn’t lose his brother. He’d blamed Dean for doing the exact same thing just months ago, and it’d been their worst fight ever. Because there was no doubt in Sam’s mind that this demonic version of his brother would disrupt the world just as bad as the devil ever could, there was no way nothing big _wouldn't_ come from a demonic Winchester.

He’d known all of these things with frightening clarity when he’d held the knife to Dean’s throat. There hadn’t been any confusion in his mind, no denial or hoping that he could cure his brother controlling his limbs. He loved _this_ Dean as well. It had been inside him ever since he’d gotten out of Hell and Sam had always loved it whenever it bled through. He should probably have taken a timeout somewhere along the road when he started getting hard from the sight of Dean with hot steel in his hand and blood splatters dripping down his body, but he was so used to almost everything about his brother making him hard that he hadn’t even been surprised at this, relatively new insight to his own subconscious.

He wanted Dean to be able to have this – to be able to enjoy himself without caring what was right and wrong. What if felt like to have _power_ He’d seen the look Dean had tried to hide on his face when the angels had him torture Alastair. It had been pure ecstasy. It had been the most real feeling Sam had seen in his brother since he’d come back from hell, the most at peace Dean had been in years. It had made Sam feel like he was willing to do anything just to make Dean feel that way all the time, because his brother deserved to feel that way. The same feelings flickered in Dean’s eyes whenever he killed something or made a demon scream since then. He always hid it carefully, it was only there for a fraction of a second and Sam would have missed it if he didn’t know his brother as well as he did and wasn’t looking for it. Dean deserved to feel _good_ Sam was beyond caring about the rest of the world – the rest of the world had never done shit for them, it was his brother’s time to be put first for one damn time.

So yeah, he still knew that he should have killed his brother and why he should have done it. But he didn’t even regret his decision not to for a fraction of a second. There was no way he could bring himself to regret not killing his brother. He’d spent his entire life loving every part of Dean, the disgusting big brother who pulled fart-jokes and played terrible pranks on him and teased him relentlessly, the protective brother who would stop at nothing to keep Sam safe and always put Sam first, the stubborn brother who refused to change the ancient cassette tapes in the impala and still insisted on paper-maps despite Sam’s constant suggestion that they switch to GPS, the easygoing Dean who could always make Sam feel better with just an affectionate smile, the constantly just out-of-reach sex-god Dean that made Sam’s adolescent years a living hell. And he was already in love with this version of Dean as well - sure, dangerous, unapologetic and still so much Dean that it made Sam’s heart ache.

He didn’t regret it despite knowing that that was the only chance he’d ever get. Despite knowing that he was giving his life over to his demonic brother, putting his fate into his hands, as well as the rest of the world’s. He trusted Dean more than what was probably sane if he was honest with himself. But it didn’t matter – he had always been at Dean’s mercy, he had always been _Dean's_ ever since he was a six month old baby being handed to him in the midst of a roaring house-fire. No matter what hurtful words they’d thrown at each other in frustration, anger and desperation, that had never changed for Sam. Countless miles between himself and his brother while he was parked in Palo Alto the part of him that made him _him_ had been on the road with Dean, in the passenger’s seat of the impala.

He didn’t regret it even when Dean’s lips worked themselves up into a smirk as if his brother could _smell_ the way Sam’s dick started to harden in his jeans when Dean’s voice became practically pornographic as he challenged Sam to _do it_ to cut his throat, to kill him. He didn’t regret it as Dean revealed his true eyes as Sam pulled the knife away, letting the weapon scatter to the floor somewhere in the corridor. For a second his eyes were glued to Dean’s, until the smirk on the demon’s face grew even wider and Sam felt like he was missing something. Dean wasn’t trying to kill him, he was moving toward him slowly, each step deliberate as if he was making a show of it. He didn’t regret not killing his brother even as his eyes fell on Dean’s throat, where the knife must have nicked his skin because drops of blood were trailing down the column of it. 

Holy shit. 

For all Sam’s consideration this very scenario hadn’t occurred to him, but even as he involuntarily licked his lips at the sight of the warm liquid against Dean’s pale throat he couldn’t bring himself to regret not killing his brother.

He didn’t regret it as he snapped his eyes back up to his brother’s face and saw the triumph there, and then realized that Dean had been planning this entire thing. Desire, want and need hit Sam like a punch to the gut as Dean stopped in front of him, close enough that only an inch separated their bodies and their breath’s mingled. The “Come on, Sammy, do it.” That left Dean’s lips in an erotic whisper went straight to Sam’s cock and fuck, that tone of voice should be _illegal_ Dean had always been irresistible to Sam, able to make him hard just by bending over the hood of the impala a certain way or smiling at him with his lips around a straw. But Sam had never been on the receiving end of Dean’s seduction, Dean had never tried to purposely make him feel anything. He heard the vibrations low in Dean’s throat and felt as if the words had been whispered in his ears while Dean’s cock was already buried deep inside him and suddenly he understood exactly why girls everywhere practically threw their panties at his brother. He would do anything that voice told him to, however impossible he would find a way. 

As Dean brought a finger to his throat and trailed it along one of the escaping drops of blood to where it spilled out of him, his finger pressing in to make more of Sam’s drug of choice well out and coat his finger, Sam still couldn’t make himself regret not killing him.

For all the darkness Dean had in him, Sam had plenty himself. He had always been more selfish than Dean, more willing to leave the masses of civilians to fend for themselves so that he could find happiness, quick to abandon his brother so that he could live a _normal_ life so that he could pretend that he wasn’t a freak. Pretend that he didn’t feel the pull toward the darkness which he could only partly blame on the demon-blood. He was in love with every aspect of his brother, but his mistress was the power he got from the demon-blood. The way he didn’t have to worry about being a freak when he was capable at making demons cower and bow before him, let the entire world try calling him freak when he was tearing it apart. 

Dean brought his finger to Sam’s face, slow enough to give Sam an out, to fight it, to give in to it. When Sam didn’t move a muscle Dean placed the finger to Sam’s mouth, dragging along the shape of his lips, coating them in red. Then the finger pressed down on his lower lip, demanding entrance and Sam drew a dragged breath as he let it inside. His dick was rock hard, even before taste of his brother’s blood registered on his taste buds. He brought his tongue to the finger and dragged it along the underside, gathering up as much of the blood he could and imagining that it was Dean’s cock he was caressing. As soon as the taste of the blood registered in Sam’s brain it was like being hit by lightning, only the lightning was _Dean_. Sam didn’t even try to hold back the desperate, surprised and completely shameless moan that he barley recognized as his own at first. Dean’s blood tasted like blood, warm and rick and bitter, but it was mixed with something that felt akin to electricity. He felt like his insides were crackling and sparking as the blood traveled through his body at the speed of light. And once he swallowed he was hit by a wave of the taste of Dean’s finger underneath the blood. Gunpowder, leather,  
sweat and Dean, a combination so wonderfully perfect that he was amazed by how he had never realized just how good his brother smelled before, how right.

Sam kept licking the finger Dean had in his mouth, just holding it there, letting Sam do all the work, and when there was just the heavy taste of Dean left he switched technique. Pulling his lips right around Dean’s finger he started sucking on it, chasing the delirious taste of the demon’s blood. No other demon’s blood had made him feel this way and he didn’t know if it was because this was Dean or if it was because Dean was special. Maybe both. He couldn’t care less at this moment.

Dean’s groan made Sam snap out of his blissed out search for every single particle of blood left on Dean’s finger, under his nails, in the crevice of his knuckles. The sound of his brother fighting with himself to regain control over his body’s response, his body’s response to Sam, made Sam’s own dick throb. He couldn’t do anything about it though, he was frozen in his spot, not wanting the moment to be over. When the trickster had forced him to relive Dean’s death over a hundred times Sam had sworn that there was nothing worse than time-loops, but he would have sold his soul then and there if it meant that he could relive sucking Dean’s blood of his finger forever.

He still didn’t regret not killing his brother when he was suddenly shoved to his knees, hitting the floor hard and only barley managing from falling flat. His brain scrambled to keep up, a big part of him still reeling in the feeling of the small amount of Dean’s blood that was now thrumming in his own veins. 

“Fuck, Sammy, fuck. So fucking…” Dean’s voice was gravel and lower than Sam had ever heard it and it was really a miracle that he hadn’t come in his pants yet. “Thought I was gonna have to fight you, lock you up, tie you down and work you over for months. But fuck you… just look at you.” Dean’s babbling didn’t make much sense but Sam didn’t care about the substance of his words, just the way his brother’s pupils had blown out of proportion and his fingers were working to open his pants. Sam had just the time to register his own _yesohmyfuckinggodyes_ before his face was two inches away from Dean’s cock. It was hard and heavy in Dean’s hand, thicker than Sam had imagined it and so fucking perfect. He licked his lips, practically salivating at the sight in front of him and looked up to meet Dean’s eyes again. His tongue darted out over his lips again, chasing a few remaining drops of his brother’s blood and Dean groaned again, deep and long and filthy. 

“Gees, you don’t even know what you’re doing to me do you? Fucking hell Sammy. You gonna let me? Gonna let me shove my dick past those gorgeous lips huh? Gonna let me fuck down your throat until you’re choking for air? Fuck, you’re not even going to fight me, are you? _Fuck_.” Dean was stroking his cock while he was talking, his eyes locked on Sam’s the entire time, his way of not blinking once eerily supernatural. He ended his rant on a long whine as and gripped the base of his cock hard, keeping himself from coming as he thought of _Sam_ , and it was just too much for the youngest Winchester. Sam closed his eyes as he came and lost control of his body, catching himself with his hands just before collapsing into a boneless pile on the floor. For a while his own breathing was all that could be heard in the corridor, heavy and he imagined that Dean could _hear_ how fucking perfect he felt just by the sounds of air pushing out of his lungs.

He was far beyond regretting not doing the right thing when one of Dean’s hands sneaked their way into his hair a few seconds later, when Sam was still somewhere over the clouds from probably the best orgasm he’d had in his life. The hand was surprisingly gentle at first, considering the fact that Dean _was_ a demon now. His thumb stroked Sam’s temple a few times and Sam gave an appreciative hum at the touch. Then the fingers tightened, pulling on a big chunk of his hair and forcing him to angel his head back enough to look Dean in the eye. He went willingly, suppressing a huff of laughter as his tick twitched inside his jeans, trying to show interest at the hair-pulling even though it had been literally seconds since he’d come. Dean was going to be the death of him, there was no doubt about that, and Sam had never felt so certain of making the right decision in his life. 

“Open up little brother.” Dean said, the smirk on his face both predatory and that of a triumphant older brother who’d just won a competition and Sam’s heart ached with love for the both of those versions of Dean. He complied with Dean’s request, opening his mouth to let his cock inside his mouth, but just the smallest opening, enough for Dean to fit the head inside but nothing more unless he wanted to bring two rows of teeth to the table. Sam moaned again when the tip of Dean’s cock touched his lips and slid past them, way beyond shame or trying to hold back the extent of his devotion for this brother. That was all out the window now. Dean looked like he was about to protest, shove his dick further into Sam’s mouth and take control, but Sam raised a challenging eyebrow at his brother. Dean huffed in amusement and before his brother could get too smug about having his little brother on his knees before him Sam worked to regain control over his body, which still felt like a melted mess of goo from his orgasm. 

He let his wet tongue swipe over the slit of his brother’s cock, one, two, three times and on the third he was rewarded by a burst of pre-come and the feel of Dean’s hand tightening in his hair. He’d never actually given a blowjob before – he wasn’t gay despite his lifelong longing for Dean and everything about Dean’s very manly body. He’d never met a guy other than Dean who he’d felt like fucking. But he’d had enough time growing up (and quite a few times while being adult as well) to imagine what he would want to do his brother, memorizing the things girls had did to him which had made his eyes roll back in his head. He was fueled by Dean’s blood swimming in his veins, almost like he could feel Dean’s appreciation himself, the blood linking them together. He took in more of his brother, slowly sliding his lips over the velvet hardness and tracing the vein on the underside with his tongue. Once he was as far as he could comfortably go he changed directions, hollowing his cheeks and sucking like he was trying to suck Dean’s orgasm out of him by force, or maybe like he could get more demon-blood in his system that way. It made Dean shiver and swear, the amount of foul words enough to make even a hunter’s ears bleed. 

Sam tried to set up a rhythm, it didn’t seem like he could to anything wrong by the way Dean was fighting to keep his knees from giving out whenever he tried a new swipe of his tongue, but it wasn’t easy and he was pretty sure that Dean had had a lot more way better blowjobs in his life. 

“Fuck, Sammy let me just…” Sam looked up at Dean’s face again once his words became coherent again and nodded around Dean’s dick, humming slightly in his throat to send vibrations through it. Anything. Anything Dean wanted. It was Dean who was obvious about never denying Sam things, about putting his own happiness aside to make sure that Dean had every little thing he asked for, but Sam was just as willing to do the same for his brother. Especially when it came to this. “Jesus Christ.” Dean mumbled as he met Sam’s eyes. The hand still holding a chunk of Sam’s hair flexing and gripping tighter was the only warning Sam got before Dean pushed his hips forward and sank his cock further into Sam’s mouth. He fought against the intrusion at first, struggling to remember how to breath and watch his teeth at the same time, his body trying to tell him that his wasn’t what it was meant for. But when Dean pulled back, almost all the way out and he regained some oxygen to his brain he was able to prepare for the next push.

Dean’s cock was thick and hot and Sam’s jaws were starting to ache from being kept open. He was starting to wonder about demonic super-stamina since enough time had spent that his own cock was working its way up to full hardness but Dean had been rock hard but still not tipping over the edge the entire time. It didn’t matter to Sam though – he’d gladly do this for hours. The reasons for why he should have killed his brother were starting to blur, to seem irrelevant and unimportant, as he concentrated on suppressing the reflex to gag as Dean kept hitting the back of his throat every second. The brutal pace he kept was dizzying and wonderful, and Sam could only imagine how he’d feel when that cock was pushing inside him in a different place. He moaned around Dean’s cock again as he got a mouthful of pre-come, the salty taste of Dean exploding in his mouth. Then suddenly Dean was pressing even further down Sam’s throat, his groin in Sam’s face and his legs shaking. The hand in Sam’s hair kept him steady, but Sam was pretty sure that it was just because Dean liked having his hand in Sam’s hair, because they younger brother made no move to pull away, despite the fact that his eyes were tearing up and he was starting to get a bit lightheaded from the lack of air. Dean made a few shallow thrusts, not pulling out more than half an inch, trying to come as far inside Sam as he physically could. A string of Sam, Sammy, of fuck, Sammy’s left Dean’s mouth but Sam wasn’t sure Dean was aware that he was saying the words. He gave a last thrust before starting to pull out, just enough that the head of his cock was still inside Sam’s mouth as he came. Sam swallowed eagerly, wanting to taste _everything_ about Dean. His blood, his lips, his come, his sweat, his fucking _feet_ if he’d been asked to at that point. 

“Jeesus.” Dean offered as Sam kept sucking on the head of his dick even after it’d stopped leaking. Sam smiled and pulled off, slowly rising to his feet, unsure of whether his legs would bear him or not. He still didn’t feel like he’d recovered from his own orgasm. But he was steadier than Dean at least, and used that to his advantage. Gently pushing his brother toward the closes wall in the corridor for support. He tucked Dean back inside his boxers and pants, leaning in to press a kiss to the corner of Dean’s mouth as his brother hissed when he touched his oversensitive cock. 

He was completely sure that he’d done the right thing when he’d decided no to kill his brother as he scraped with his fingernails down Dean’s throat, catching the dried up little rivers of blood on his fingers and bringing them to his mouth. Once he’d sucked them clean he looked back at Dean who was staring at him under half-lidded eyes, the hunger in them making Sam’s stomach flutter. Oh yes, he’d chosen well.

“Hey Sammy” Dean said, smiling in a way that would probably scare the death out of anyone other than Sam.

“Yeah?” Sam breathed out, feeling like Dean’s emotions were bleeding over into his own though the blood as he was starting to feel giddy with excitement at whatever Dean wanted to tell him.

“Let’s kill some evil sons of bitches and raise a little hell, huh?”

“Got anyone particular sons of bitches in mind?” Sam asked, waiting to feel sympathy for whoever was going to end up at the top of Dean’s list, but coming up empty. The only thing he felt was excitement at the thought of seeing this new, unleashed Dean in action.

“Oh yeah, I can think of a few.” Dean answered and his eyes went entirely black.

“Fuck.” Sam hadn’t meant to mutter the word out loud and he kind of hoped that Dean wouldn’t notice the groan inside it. He didn’t though, of course.

“Like that, huh?” Dean said teasingly, but there was a thickness to his tone that revealed just how hot he thought that was and that kind of took the edge out of the teasing. 

“Yeah.” Sam said simply since there was no reason to hide the fact. “Just like I’m going to like holding you up and fucking you against the wall of the shower we are about to take in a few minutes.” He managed to get the entire sentence out without his voice shaking or wavering and he was pretty damn proud of himself for that. He was pretty sure that Dean had filled his quota on how many times a day a person (demon) was allowed to say fuck, but the way Dean said it now, three times in a row, hurried as if he was already getting fucked, made Sam shiver. 

There was no way Sam could regret anything that made Dean look at him like that. If the world burned as a consequence of his choices, let it fucking burn. He’d light the match himself if that was the path he and Dean were heading down, as long as they did it together.


End file.
